package com.Utils;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.PDFRenderer;

import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import java.awt.image.BufferedImage;
import java.io.*;


//-----------------------------用于转换pdf为png-------------------------------

public class PdftoPng {
    /*
     * *
     * 实现pdf文件转换为png
     * 参数是第一个是要转的转换的是pdffile
     * 第二个参数是是要存储的png图片的路径
     */
    public static void pdfFileToImage(File pdffile, String targetPath) {
        try {
            FileInputStream instream = new FileInputStream(pdffile);
            InputStream byteInputStream = null;
            try {
                PDDocument doc = PDDocument.load(instream);
                PDFRenderer renderer = new PDFRenderer(doc);
                int pageCount = doc.getNumberOfPages();
                if (pageCount > 0) {
                    BufferedImage image = renderer.renderImage(0, 2.0f);
                    image.flush();
                    ByteArrayOutputStream bs = new ByteArrayOutputStream();
                    ImageOutputStream imOut;
                    imOut = ImageIO.createImageOutputStream(bs);
                    ImageIO.write(image, "png", imOut);
                    byteInputStream = new ByteArrayInputStream(bs.toByteArray());
                    imOut.close();
                    bs.close();
                    byteInputStream.close();
                    doc.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            File uploadFile = new File(targetPath);
            FileOutputStream fops;
            fops = new FileOutputStream(uploadFile);
            try {
                fops.write(readInputStream(byteInputStream));
            } catch (Exception e) {
                System.out.println("--!:"+pdffile.getAbsolutePath()+ "pdfFile  may be damaged");
            }
            fops.flush();
            fops.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public static byte[] readInputStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;

            while ((len = inStream.read(buffer)) != -1) {
                outStream.write(buffer, 0, len);
            }

        inStream.close();
        return outStream.toByteArray();
    }
}
